H2No!
by RicePoison
Summary: [Now being updated on AO3]. Marinette and Co. sail out to sea on the Agreste yacht, bound for Miraculous Island! However their adventure is cut short by a series of incidents, someone wants them off the island. Will Marinette and Adrien, Nino, and Alya figure out what Miraculous Island is hiding? Or will they become lost in the sea mist?
1. Chapter 1

_The moon pool, a key feature of Miraculous Island had laid undisturbed for years now. The cool water from the ocean rushed into the grotto, circling before it returned to where it came. In a volcanic caldera, it was hidden from the rest of the island, the only way to enter was from the ocean - or that's what was known._

Flipping through her geography textbook, Marinette paused as she looked at the island illustrated, barely hearing Alya ask her something. Dreaming she heard Alya ask again, muffled… and again, clearer…

"Marinette! I need to know if you're coming with us to the Island."

"Oh yea, that's this weekend, right?" Marinette closed her book. Alya had arranged with Nino and Adrien that they'd head out to one of the islands off the coast for a camping trip. She put her book back into her bag as her and Alya packed up. "Did we need to bring anything? Was it going to rain this weekend? I've got rain ponchos!"

"Don't worry so much, Marinette. Adrien has everything we need on his father's yacht." Alya reassured her friend, getting up to leave. "I'll see you guys tomorrow morning, bright and early!"

Marinette shifted uncomfortably, realizing how early Alya was referring to, groaning at the thought of 6am as her friend laughed. "So.. how early should we be at the docks?"

* * *

Adrien was the first to arrive with Nino, his bodyguard towering over him like a massive… gorilla. Might be why they call him that, maybe. Marinette giggled at the resemblance as she rolled her small suitcase up behind her - containing most of her belongings. She noted that Nino had brought an excess of supplies, backpacks, and bubble wands — for whatever reason was a mystery to Marinette. They waved her over as Gorilla stoically looked towards her.

Alya nudged her side, having just arrived. "You're staring again."

"I can't help it, Alya! Three days on an island with… _Adrien_." a blush covered her face as she swooned, then shaking her head as the two walked forwards. "How far out is this island?"

"Girl, have you been paying any attention in Geography class? We're going to Miraculous Island!" Alya smirked, pulling Marinette's hands forward as she pulled her smirk into a grin. "It's not only the most mysterious island, but it's got an _amazing_ beach!"

"I didn't pack my swimsuit!" the thought hadn't crossed Marinette's mind until now. she frantically looked to Alya as her friend laughed again. "I guess I can borrow one of yours…?"

"C'mon guys! We want to get out there before Lunch, right?" Nino motioned to the yacht as Adrien and Gorilla turned to board. "You brought the croissants, right Marinette?"

"That's the one thing she didn't forget." Alya answered for her, pulling Marinette along to the boat.

* * *

 **[2 hours later… because being on a boat takes a long time if you're crossing an ocean]**

"Land ho!" Nino called, somehow Gorilla had allowed him the 'responsibility' to use the ship's intercom system. Marinette shook her head out of a sleepy haze, having fell asleep in one of the deck chairs, she looked around to get orientated again. Standing upright, she walked to the railing, looking over to the sea below. They had anchored further out due to their boat's size, so they were further from land than Marinette had anticipated.

"How are we going to get over there?" Alya had joined her, looking down at the water "I bet there are sharks this far out." a clacking noise was heard from the left, Gorilla had begun to lower one of the attached life boats, motioning for the kids to come over. Alya left the railing, pulling Marinette's bag with her "Stop your daydreaming and come on!"

Marinette stopped, then running over to Alya. Adrien had already helped Nino into the lifeboat, Alya decided once Adrien extended his hand to her that she didn't need help - hopping into the boat with a fox-like grin on her face. Adrien looked at her before smiling at Marinette, his hand extended to help her into the boat. "I-I… why don't you go first?"

"I should help you, since I invited you." Adrien was quick to grab her hand and help her over the gap. She looked down for a quick second seeing the opening between the yacht and the lifeboat, a drop to the ocean that was probably teeming with sharks! In her brief moment of panic, she jumped in, tripping over her own suitcase and she would've gone further if Alya hadn't of grabbed her.

"Careful, what are we going to do with you if you fall in the ocean?" Alya chuckled, helping her friend sit down as she also helped Adrien get in the boat. A quick motion to Gorilla and the lifeboat was lowered to the water. "Besides, our Geography textbook said that its too cold for sharks here."

"ALYA!" Marinette shot a look towards Alya as she laughed again. "Next time tell me if there are _actually_ sharks in the water."

Alya nodded, smiling widely as she waved at Gorilla. "I have a feeling that this is going to be a fun weekend!"

 **A/N: I'm not dead!** Okay, right now I've found myself caught up in a college strike, so I have time to write! At this time I'm not continuing with Coccinelles et Chats - _that will be continued as a one-shot in the future, so if you were a fan of it, stay tuned_. I fell back into love with _H2O Just add Water_ recently by binge watching all of _Mako Mermaids_ \- whoops. Anyhow, this fic is in they style of that... so yeah: Mermaid!AU in the style of _Mako Mermaids,_ so y'know, at one point... things are going to get a bit fishy.  
Thanks for reading! - Rice 


	2. Chapter 2

Nino helped Adrien pull their lifeboat onto the beach. Sparkling white sand, contrasted with the deep green jungle beyond, and the extinct volcanic structure in the distance — Alya was not the only one taking in notes about this island. Marinette hopped over the side of the boat, ankle deep in frigid ocean water, she ignored the initial shock of the cold water, walking on shore as the sand squished between her toes.

"It's weird this island is relatively uninhabited, it seems like a cool place!" Nino slung his backpack over his shoulder, Marinette's much-less practical rolling suitcase in his other hand. "The established campsite is a bit in from here, near the river. I'll go ahead and find the path." he went to venture on ahead, although only a short few meters in front of the rest of them.

"Wait, where's my bag?" Marinette looked in the lifeboat, having not noticed Nino taking it.

"I've got it!" Nino exclaimed, waving them over "The trail is here, let's go!"

* * *

 **[A little while later - lots of walking was involved]**

Alya sat down on a large grey stone, glaring at Nino. "You said you knew the way."

"We're here now." Adrien sat across from her and Nino. "All we have left is to set up the tent — luckily my father lent us the new tents from his line!" he hopped up, opening the backpack nearest to him, a collapsed round disc of purple fabric was nestled safely inside. With a swift flick of his wrist, the disk popped out into one small tent, enough for Alya and Marinette, then a second one for him and Nino.

Alya examined the purple patterned fabric. "What's your dad's thing with butterflies?"

"It's his logo. He has to include it somehow. Besides, we can appreciate he actually contributed … well it might've been mostly Nathalie… but its the thought that counts, right?" Adrien shrugged, looking back at the tents. "I'm gonna… go for a walk." he turned on his heel, walking down one of the trodden paths through the jungle.

"Shouldn't we try to stop him?" Marinette tried to voice her concern, however Alya shook her head.

"The boy needs some alone time. He'll come back when he's ready."

* * *

The undergrowth pulled at his heels, however he continued through the dense jungle until he reached a rocky outcrop by the river. Adrien turned, walking onto the damp stones as he muttered to himself, trying to think of something other than the butterfly-clad tents that Nathalie had obviously arranged in place of his father. Upon pausing, then turning, he lost his footing, slipping on the algae coated river stones. The rest happened too fast for his liking - one moment he was up in broad daylight, the next, he was slipping down a narrow passage, depositing him onto a bed of soft sand. "What…" he got up slowly, making sure he hadn't been injured during the fall. "…is this place?"

A sparkling grotto before him, white sand beneath his feet, something about it looked so… preserved. He walked forwards, looking into the water. It looked like it went all the way through to the ocean, perhaps? He didn't want to take any chances, nor did he want to be stuck down here. No one would find him, his father probably wouldn't look for him. Adrien gazed at the rocky wall behind the pool, a purple shard of light catching his eye — a butterfly? He breathed, watching the black insect lift it's wings and fly towards him, encouraging him to move.

"I'm sick of butterflies!" he instantly dove into the pool, avoiding the butterfly landing on him. The frigid water a shock to him, he kicked further, knocking his shoulders against the bottom of the pool. Adrien opened his eyes, looking up at a coral as he tried to get orientated. There was something on the coral, but he needed air — fast. Emerging for a breath, he watched as the butterfly circled the pool, not taking notice to Adrien yet as he dove again, grabbing at the object on the coral. He looked down again, trying to swim to the ocean exit, but then deciding against it. He emerged, opening his hand to reveal a silver ring with a black crystal.

"What's this doing here?" he slid the ring onto his finger, starting to pull himself out of the water. The butterfly landed in front of him, he scowled "Does it take a _cataclysm_ for you to go away?" instantly his ring sparked with a bright green glow, the butterfly burning away in front of him. Adrien… well he didn't know what to think, instantly recoiling in surprise, and letting go of the side of the pool. "What was that?"

* * *

 **[Back at the Campsite, nearing 10:30pm…]**

"I think we should go check on Adrien. It's been a while, maybe he's hurt?" Marinette had been worried the entire time, vocalizing her concern to Alya and Nino (who were still preparing the campsite). Nino looked up from the campfire kraft dinner he was making for all of them, shrugging to Marinette. "Fine. If you guys aren't going to do it, I'll go look for him!"

"Ooh, while you're gone, can you get some pics of the solstice moon?" Alya ran over to Marinette, handing her the pocket camera she had packed in her backpack. "You'd probably get a good vantage point to look for Adrien from the side of the mountain!" there seemed to be no concern in her voice, probably because the island was known for camping and no incidents had occurred.

 _Yet…_ it echoed in Marinette's mind that something might go wrong. She put the camera in her pocket. "I should be back in an hour."

* * *

Although the thought of going alone through the jungle scared Marinette, she followed the path along the stream. Seeing nothing, she started to climb the rocks, flitting her phone flashlight in every spot she thought Adrien might be. "He couldn't of gotten far, the island is smaller than Paris." She cast a look on the outcrop, sighing before scaling the volcano.


	3. Chapter 3

It must've been nearing midnight, Marinette was almost halfway up the volcano when she looked around. The moon was almost directly over the volcano, causing all the rocks around Marinette to illuminate in silver light — something caught her eye a few feet down from her, a purple glow among the silver moonlight. Marinette turned, to slide down the exposed basalt stone, which was quite damp — despite it having not rained yet. She brought her phone up as she looked for the bright glow again, shutting it off once she established that it was a cave, with a light source inside? I should get Alya and Nino. She was about to turn on her heels and head back. But what if Adrien is in there? Marinette took a step in, walking towards the faintest purple glow of another corridor in front of her. "Hello? Adrien?"

A rustle stopped her, she turned around to find the entry she had passed through to be gone. That… can't be! Am I trapped in here? Panickedly, she felt for the door, but instead a cool stone wall was in its place. She turned again, inhaling shakily as she walked again towards the light. To her surprise, even though the stones were cold, the air was warm — as if someone had been there prior to her. She hoped it was Adrien as she turned the corner, revealing a whole room illuminated in purple light. "Adrien?"

"How'd you get in here?"

Marinette froze. That wasn't Adrien. She raised her head to see the face of a masked man, shaking, she took a step back. Where's Adrien? Who is this man? Why is he in here? How am I getting out of here? She yelped as the ground seemingly started to give under her feet, eyes wildly flashing towards the man as he raised his arms.

"Begone!" a flash, several white butterflies extended from the man's form, turning black as the started to swarm above his head, then towards her. She ducked, unfortunately sucking her further into the floor. "Get out!" was the last shout she heard before being pulled completely into the quicksand that surrounded her.

* * *

[Just below that chamber… back in the grotto]

Adrien had given up scaling the wall to get back to the tunnel. He sighed, sitting back down at the edge of the pool - even if someone had been looking for him, if they came down into the grotto, they'd be stuck as well. He gazed up, watching the moon start to crest over the top of the volcano, bathing him in silver light, hearing a distinct sound of water bubbling. Adrien quickly redirected his gaze to the pool, the water bubbling in reaction to the moon's light. Another sound, he looked up once more to see a purple glow in the wall above the pool, a tunnel appearing as someone quickly shot out. "Marinette!" he panicked, watching as she hit her head on the side of the pool and slipped under the bubbling water.

"Marinette!" Adrien's first instinct kicked in, diving into the pool after her. He pulled his hands around her torso and swam back to the surface, looking up at the moon as it finally illuminated the whole grotto. He looked back at Marinette, who was out cold from the blow to her head. "Marinette, wake up!" He could barely hear himself think as the bubbling water raged around him, he stopped as e couldn't feel his lower half. Maybe the pool was volcanic? Maybe it had burned his legs off? He couldn't see anything in the water, still trying to tread to keep Marinette's head above the bubbles. Then as suddenly as it began, the moon started to move away from the top of the crater, the bubbles suddenly ceased.

Adrien looked down at his friend, and then further down. His eyes widened seeing a fish-like tail extending from her torso, almost dropping her out of shock. No, this isn't the time for this, Agreste! Get her out of the water! Adrien pushed his weight up from the side of the pool, lifting Marinette back onto the white sand before attempting to get a leg up on the side of the pool. He fell backwards, seeing his legs — well not his legs, he found his own tail extending in front of him. What's going on? He looked around, trying to find something to answer his questions before pulling himself together. He pulled himself up on the sand, then shimmying his way over to his friend.

"This can't be happening, Marinette, wake up." He dipped his head to her mouth, attempting to perform CPR, as it was the only thing on his mind to help her come back. He paused between his compressions, listening for her breath, then trying again. On his third try, she coughed a mouthful of water out, Adrien putting an arm around her back as he lifted her to an upright position. She hadn't opened her eyes yet, which was when Adrien realized — they were both still in a fishy situation. He could've laughed at that pun but instead brought her back to the side of the pool. "Ring, if you can… please transform me. She can't see me like this." an awkward request towards a piece of jewelry, but the bright green flash that enveloped him was enough to say that it indeed heard him.

"A-Adrien…?"

"He's safe, rest up. You hit your head really hard falling into the pool." Adrien slinked back into the water, his new form had coated his arms in black scales, as well as around his eyes. He turned around in the pool, swimming back up to her. A black tail circled behind him as he propped himself up on the side of the pool. "Lucky for you I was here to keep you from drowning."

"Who—" Marinette held her head, then opening her eyes as she saw both him and her own tail. "What happened to me?!"

"I'm not sure what happened to you." Adrien looked at her again, then looking at his own ring. Thank goodness that worked, I'm not sure how I could explain to Mari how we're both … fish. He pulled himself up beside her. "You know, with that tail, you'd probably be able to swim out of here."

"How do I turn back?" Marinette's panic was unsettling for him, he didn't like to see his friend in distress so he simply took her hand, pulling her into the pool. "You—"

"Chat Noir. You can call me that. Let's get you out of here first, then we can work on the details." another pull of her hand as she slipped back into the ocean water with him. Adrien shook his head, at least it was a better alias than Cat Fish. He took a breath, although probably uneccesary, and dove under, still holding Marinette's hand while pulling her downwards, towards the tunnel to the ocean. He turned to look at her, trying to give a reassuring smile even though he had no clue where he was going. A powerful kick — was it still a kick if he didn't have legs? — and he led both of them through the tunnel, hitting something on the end. Metal bars? Why were these here? He quickly turned back to the pool, coming back up.

"So we're trapped in here? How'd you get in?" Marinette looked at him, suspiciously almost.

Did I say something before to get rid of that butterfly, maybe I can try it here! Chat circled the pool, muttering under his breath "Cataclysm" before diving back down. Swimming to the end of the tunnel, he grasped the bars with one hand, watching the ring on his other hand start to spark back up again, a black energy coating over his hand — he looked from this to the bars, pressing his hand against them. He swam backwards as the black energy coated the bars, rusting them into a state of disrepair. He swam forwards again, pushing himself off the bars with his tail and shooting back up into the pool. "Marinette—"

He looked up, the girl already determined to get out of the grotto had pulled herself up onto the sand, reaching for the far wall to pull herself further out of the water. She grabbed something on the wall before flipping over to look at him. "How'd you get in here, Chat Noir?" he watched as she affixed something to each ear - an earring? He couldn't tell from the pool what exactly she had grabbed from the wall. She repeated her question when he realized he had been staring. "How'd you get in?"

"I fell." Chat sheepishly admitted, he looked down at his ring, which had illuminated from the center in a paw print pattern. "Not as you did though, its solid rock up there, not sure how you phased through that."

Marinette flipped back over, pulling herself up as a glitter took on her scales, fading them away into the room around them. She turned, almost tripping as she looked at her legs. "How?" she walked back to the pool. "How are we getting out of here then, kitty?"

"Kitty…?" Chat paused, looking at her. "Oh right! I used my powers to break open the bars! All we have to do is swim out of…" He stopped, scanning her from her hips to her feet — completely dry. He was unsure if she could transform back, although the furthest thing from his mind was whether or not he could turn back himself. "Right, looks like that was temporary. I could carry you out, but I'm not sure how long you can hold your breath." he flicked a hand at her, water droplets colliding with her face, she flinched. "Oh my god, I'm sorry, are you okay?"

"I'm fine. Looks like once transformed back you won't—" she paused, a stunned expression sprawling across her face as she fell forwards into the pool, a pink tail appearing in place of her legs. Chat grabbed her before she could drift further, pulling her back up. "Argh does that mean I can't go near water?"

"Well it looks like you're in it, purrincess." Chat stopped Was that a cat pun? Why am I joking right now, we should be getting out of here! his ring flashed, the pattern starting to dissolve away. I don't think I have much time either! He looked back at Marinette, grabbing her hand as he dove again, pulling her through the dark sea tunnel and emerging in the ocean on the other side. Coming back up for air, he turned to Marinette. "I need you to go back to your campsite. I have to… check the reef!"

"Alright… I think I'm fine here." Marinette turned as she watched Chat Noir dive again, a brilliant green flash following his path through the water. She started pulling herself on shore, feeling her ears for the strange silver earrings she had collected in the grotto. It was weird to her that someone would've left them down there, especially since the only escape route seemed to be through the pool. "Wait." she turned as her tail reverted back to legs, pink sparkles fading into the night sky. "After all that, where's Adrien?

A/N: I think my toughest challenge for this is going to be working in a couple of aquatic super heroes. Also my need for coffee and being out of milk and I should go buy more. Wait. How is that relevant? Not really, just shows I'm not the person to drink black coffee and work on FanFics at the same time. Anyhow, trying not to make this overly confusing or make the love square into a love rectangle with two extra points... trying is the key word. I'll try to get a new chapter out every two days or so. Eight chapters. Maybe a reveal. Camembert. Something.


	4. Chapter 4

Adrien pulled himself up on the shore, a fair distance from where he left Marinette, but still pretty close to the campsite. At least, that's what he figured, hearing the sound of the stream that they had probably set their tents next to. Looking down, his green tail glinted in the moonlight, the ring on his finger reflecting the moon back at him. "Before I figure out what all that was, I should get back to the camp. Marinette was pretty worried."

Looking around for something to dry his scales, he pulled himself onto the rocks, bending his knee up as he surveyed the area around him. No one for miles, he sighed as green sparkles started to fly around his ears, his tail disappearing completely as he continued to look at the ocean. A rustle behind him caused him to turn, stepping off the rock. "Marinette, you're still up?"

"I was worried about you! I mean, Nino and Alya, all of us, we were worried if something happened to you!" for someone who was just a fish, she kept her demeanor quite well towards him. He chuckled, smiling at her. "What happened to you? I thought you had fallen into—" she stopped, looking away, her concern still laced on her words "Just... be careful, okay? I don't know what I'd do if something happened to you… or any of my friends!"

"Thanks, Marinette, for your concern." Adrien stood up, walking to his friend as he looked back at the beach and ocean. "It's almost strange, this whole island feels like it's alive, doesn't it?" a quick turn on his heel as he looked back at Marinette, a scratch down on her cheek was revealed in the moonlight. He stopped, had he not noticed it before? Was that where she hit her head on the way into the pool? Adrien reached out for her cheek, concerned. "Where'd you get—"

"I slipped on the rocks. Don't worry, it'll be fine, let's get back to the camp, ok?" a bit flustered, she pulled back from Adrien, turning to head into the jungle. The leaves snagged at his jeans again as he followed her back towards the campsite, smelling the woodsmoke from the extinguished fire and a pot of cold kraft dinner off to the side, Marinette sighed "I guess we were both gone a long time. Alya and Nino both seem to be asleep." She picked up the pot, moving over to the stream to wash it.

"Wait!" Adrien sprung up, a wild expression in her eyes met his as he walked over, trying to think of something to say that didn't include _don't touch the water you'll get a tail!_ he paused, looking from the stream to her. "I don't think we should wash pots for food in that stream. Who knows what type of bacteria is in that water?"

Marinette was stubborn, he had to admit. She reached down to the water anyhow with the pot, swished the bowl through the water a few times and picked it back up. "See, perfectly fine, the KD just washed right off, we don't need to worry about—" she looked in the pot, cheese still sticking to the side of the cast iron material, she shook her head, thrusting the partially washed pot into Adrien's hands. He almost dropped the pot too, not because it was heavy, but because there was water on the outside now.

 _Panic_. Tossing the metal into the jungle, he dashed off into the dense forest again. _28… 29… 30…_ THUMP. Droplets of magical water floated off of Adrien as he propped himself back up. _I should've just told her to leave it_. He looked at his tail, sighing. _How am I going to get rid of this_? Adrien held his hand over his tail, trying to feel if the scales were wet or not, which to his relief they were only slightly damp.

"ADRIEN?"

Oh no, back to not having much time. He brought his hand across his face, thinking that would at least hide him… because he had no other options. Marinette ran right past him, yelling his name through the jungle. _Wait, she didn't see me?_ Adrien raised his hand, watching the forest take a liquid appearance and then revert to normal. _Was I… invisible?_ Adrien watched the green sparkles fly off again, instantly launching himself after Marinette. "I'm fine! Come back, okay?"

Marinette turned quickly and ran back to Adrien. "What was that about, why'd you run off?"

"Oh, the pot you handed me was still a bit hot, I didn't want to burn myself so I was looking for some sort of leaves to handle it with." he didn't like lying to her, but it was the best he could do in this situation. He started back to the campsite but turned when he didn't hear Marinette follow. "What's wrong?"

"I…"

"What happened, Mari?" Adrien looked at his friend, then noticed what she was looking at — storm clouds gathering, circling over the volcano. He swallowed hard as Marinette fidgeted in front of him, obviously thinking of some way to stay dry.

"It's going to rain, remember the weather forecast? Maybe we should go wait it out in the tent! Yeah!" Marinette continued to fidget, not showing the worry in her eyes to Adrien, but he could feel it. "Not that I don't mind being on this island, exploring would be nice but in the rain, nahhhh…."

Adrien nodded, looking at the clouds brewing above. "Y'know, I don't want to get soaked either. But I can't control the weather, if I could though, I would make sure it was sunny all day, then we could…" he paused, looking at the ominous black butterfly hovering over Marinette's shoulder. "Mari, come over here, there's a—" she looked down at the butterfly, then moving quickly towards Adrien as it fluttered closer to both of their faces. "I'm not even sure what type of butterfly this is, but it seriously has to go."

"I've seen this before! I was attacked by a swarm of them while I was looking for you!" She stopped, looking at him "You're not going to believe me though, it seemed so real, but it happened so fast."

"Mari?"

"Nevermind, Adrien. Don't let it worry you, I'm fine." she swatted her hand at the butterfly, trying to push it away from both of them. She swallowed, audibly, nervous at the small insect that flew closer to her face as she turned to jog back to the campsite with Adrien.

"What attacked you earlier?"

"There was a cave, there was a man inside. He kept telling me to get out, then he somehow made the butterflies attack me." Marinette breathed "You probably don't believe me."

Adrien would've admitted it was farfetched if he hadn't of been in the grotto. "What happened? How'd you get out?"

"I fell, through the floor, into a cave." She looked aside, catching up to him when she reached the tent. "I climbed out though, the butterflies didn't follow me." A drop. Marinette flinched, wiping it off quickly with her sleeve. "I think I forgot something in the lifeboat, I'm going to head back to the beach."

Adrien tried to grab her, but she bolted quicker than he could stop her. "At least she didn't stick around, I'm not sure how I'd explain to Alya and Nino—" he paused, feeling another drop on his own shoulder, turning quickly, he bolted towards the beach after Marinette. _19… 20… 21…_ he stopped for a brief second, seeing her pull something out of the lifeboat, the waves surging around her sneakers. _22.. 23…_ he made another quick decision, running towards her as she opened an umbrella, obviously not helping her situation as it was full of water.

"Adrien? Go back to the camp, I'm fine!" She paused, a stunned look taking over her face as she stepped back quickly. Adrien tackled her into the sand, looking quickly up at the yacht anchored only 60 feet off of the beach. _28… 29… 30…_ the waves washed over them as he kicked off the sand, plunging them both into the salty brine.


	5. Chapter 5

Marinette could only hear the roar of the ocean in her ears, feeling herself dragged under the waves she tried to look up at what was causing her to become deadweight. Finding she was on the wrong side of whoever was pulling her under, she gave a swift kick of her fins, detaching herself from their grip. Upon turning once more, she saw a veil of bubbles, covering her vision from whoever was holding her. _He can't see me like this! Can I transform…?_

Adrien was pushed back by her kick, coming up for air. Did he even have to keep coming up for air if he had fins? He stopped, noticing she had not come back up yet, looking at his ring. "No use now, she knows I tackled her on the beach, right?" he dove again, looking for Marinette as he scanned the reef. Where did she go? He turned quickly, swirling back to where he had tackled her, suddenly feeling a tug on his fin. He turned again, the bubbly veil settling a set of blue wide eyes met his.

Marinette opened her mouth, as if to gasp, but instead looked surprised as she swam back up to the surface, coughing out a collected mouthful of water. She brushed her hair off the red and black patterned scales around her eyes, oh thank goodness that little plea for a disguise worked. "I thought I was the only one down there!"

"Did you happen to see a girl with black hair and pink go by?" Adrien wasn't sure whether to tell this girl whether Marinette had a tail or legs. he curiously looked at her, then down through the water to see her tail - red with black spots. He almost breathed a sigh of relief knowing that it was not Marinette. A few more drops of rain hit around them, the sky opening up for a minute before becoming a downpour.

"Unfortunately I didn't see your friend. Perhaps she's still on shore?"

"No, she can't." Adrien shook his head, watching her surprised expression as the waves finally carried Marinette's umbrella past them. He grabbed the waterlogged canvas, pulling it up before pointing at himself. "She's also … this."

Marinette paused, looking at him carefully. _This? You mean a fish? How do you know that?_ She paused "I'm Ladybug. What's your name?"

"Adrien." he was about to continue, but instead paused when he saw a dark shape below them. Too small to be a whale, too big to be a fish… but they were close enough to shore— "Ladybug, is that a…"

Ladybug almost freaked out, kicking her tail so she was a bit closer to Adrien. Alya said the water was too cold for sharks, but why was there one now? She turned, ladybugs were good luck, right? "All we need is a _Lucky Charm_." as soon as the words escaped her lips, her hands glowed pink as an inflatable raft sprung up from under them, lifting both of them above the waves.

Adrien looked over the edge of the raft, the shark still circling below them. "What does it want?"

"Why are you asking me? I can't communicate with fish!" Ladybug struggled to pull herself up, her tail pinning her to the bottom of the raft. She swallowed hard, trying to think of something as the shark bumped against the side of the raft, pushing them further out to sea.

 _Get off my island and give me your Miraculous!_

"Miraculous?" Adrien looked down at the shark as it bumped the boat again.

"You heard that too, I thought I was starting to hear… voices…" Ladybug propped herself up, a beeping noise sounding from her earrings. "I don't think I have much time, Adrien, I'll try to distract the shark, you paddle this raft back to shore!" she jumped from the boat, the shark following in her wake as she dove.

"Well, looks like we can hear fish talking. Huh." Adrien slid back into the water "Transform me!" a bright green light emitting from his body as he became Chat Noir once again, turning to follow Ladybug and the shark through the surf, he pushed himself to grab her and skid up onto the beach, the shark following as it beached itself.

 _Give me your Miraculous!_

"This crook seems a bit fishy don't you agree, Ladybug?" she didn't laugh at the pun as he coiled his tail up, about to spring forwards. "CATACLYSM!" he shouted, his hand extended as he crashed into the shark, black energy wafting up from the sea creature — and finally, a purple and black butterfly.

Ladybug turned, springing up to catch the butterfly in the same manner as Chat had done. She covered it with her hand, then blew through the spaces in her fingers, the butterfly becoming a mist of white sparkles. Finding she could stand, she blew the sparkles onto the shark before nudging it back into the ocean with her… foot? Ladybug turned to look at Chat as the shark swam off.

"So, we defeat those, we get legs. Interesting." he pulled at the skintight black suit that now covered his body. "Hey, maybe that means we're human now, right Ladybug?" he looked down at his ring as the emblem in the middle began to fade away.

Ladybug looked at the ocean, seeing the clouds begin to clear. "I'm going to check for that boy I was talking to before you showed up." She squinted at the life raft in the distance, Chat Noir taking the opportunity to run into the jungle and de-transform. He made a bolt for the campsite, not looking back at Ladybug. "Chat—" Ladybug turned, looking at the jungle, trying to see her partner. She gave up, her transformation burning off of her as she looked back at the ocean. "I'll have to get the boat keys from Nino before I head out there again."

* * *

 **[Back at the Campsite** ]

Adrien crawled into his tent, pulling his sleeping bag around him, he sighed. Marinette definitely plunged into the ocean with him, but where did she go? Exhaling, he heard footsteps outside the tent. A phone flashlight shone through the entrance as he squinted up at the shy girl he had been looking for. "Marinette! Where have you been?"

"I went to get an umbrella, but got caught in the rain. I had to wait it out until it cleared to get back here. You?" she breathed heavily, looking at Adrien as he opened the side of his sleeping bag. "I-I can't! It wouldn't be polite—"

"You're cold, get in." Adrien motioned her to come over, pushing the side of the tent. Unbeknownst to the both of them, a pocket of water still remained by the entrance, held up by the canvas. Pushing the side of the tent, with the swift motion of Marinette fastening the zipper at the same time was enough to pour the pocket of water onto Marinette's back. She yelped from the chill as Adrien rushed up to cover her with the sleeping bag.

"A-Adrien!" a flustered expression covered her face as she buried her face in his chest. _18… 19… 20…_ "I can't, I have to go, you can't—" _26… 27… 28… 29…_ Adrien stopped counting as his friend slumped against him. He placed a hand under her knees, not raising the sleeping bag for her sake and sat back down in the corner. Marinette's face burned, but she looked back up at him.

Adrien sighed, removing his hand from under her knee and looking down at his friend. "Why do you think I was so concerned of you running down to the lifeboat to get an umbrella all on your own?"

"Because you're my friend, so you were concerned?" she grinned, hoping her response would be enough to satiate Adrien's questions. _Oh please, oh please, don't ask about… this._ She paused, looking up into his eyes as he shook his head.

"No, Marinette." Adrien pulled her up to his chin, looking in her electric blue eyes. She gasped as he reached around her back — but to her surprise he pulled the sleeping bag off of her, exposing her tail. "You need to dry off, after that we can talk a bit more, okay?"

 **A/N** : ooh ... where am I going with this? I've got some big plans coming up so stay tuned. Might include a run in with the man in the cave (or 'Merman Chamber' if you've checked out Mako Mermaids). Thanks for reading, and thanks for the reviews! 


	6. Chapter 6

Adrien glanced over at Marinette as she ran the towel he had packed over her tail. She had told him not to look, but he kept looking over to check whether or not she had transformed back. He breathed, changing his glance to his own feet when he heart her ask: "So, how'd you find out?"

Leaning back, he eyed the puddle by the doorway of the tent. He breathed _Okay, Agreste, how are you going to explain this one_? "I might've saw you pull yourself from the water earlier tonight. There was a brilliant green flash and I went to check it, and you were just getting out."

Marinette frowned, continuing to dry her tail as he moved closer to her, still eyeing the puddle. "And pushing me into the ocean, then dramatically vanishing while I was up to my shoulders in salt water, what were you thinking?"

"Gorilla and Nathalie are able to see the beach from the yacht."

She couldn't exactly argue with that. She looked at the puddle again as pink sparkles began to rise around her, tail transforming into legs. She exhaled, looking at Adrien. "And how did you know I had to dry off to turn back?"

Adrien's jaw dropped, finding no suitable way to answer that question as Marinette raised her hand over the puddle, eying her friend as she raised an eyebrow in concentration — the puddle producing a small sphere of water, which levitated below her hand. She raised her hand shakily, watching the water droplet in front of her as she threw it towards him.

Adrien flinched as he raised his own hand, the droplet stopping in mid-air. Marinette's eyes wide as he tossed it back towards the puddle, another motion made with his hand to freeze the liquid. "It's getting late. You're probably tired with all that has happened tonight." Adrien looked aside at her sleeping bag, partially frozen to the ground. He raised his arm and his sleeping bag as if to invite her to share. She shook her head rapidly as if to decline, but he motioned her to come over. "We can't have you transform due to a wet sleeping bag. Just for tonight, okay? Get some rest."

Her cheeks flushed with a brilliant pink, she moved over — her heart pounding, probably loud enough that even he could hear. He pulled the bag over her shoulders, an arm raised to allow her to settle in next to him. "We'll figure this out in the morning, I guess." She quickly turned her back to him, pulling the sleeping bag over herself. Adrien smiled, turning the opposite direction.

* * *

 **[Miraculous Moon Chamber]**

Within the cave of glowing butterflies, the man that had commanded Marinette to leave pressed his hand roughly against a stone pedestal outlining the geographic features of the island. He put his hand over the circle representing the Miraculous Pool, trying to feel a pulse of something below. "They removed the Miraculouses from the grotto. I had specifically defeated their previous holders there in order to collect them tonight, and now they're out of reach." He straightened his back, moving to the water cascading from the ceiling. Pale grey eyes scaled the wall of water, looking for a response as a brilliant violet light burned across his body.

 _How are you going to solve this?_ a voice echoed through his head he continued to stare through the clear liquid to the abyss beyond. He paused, pulling a phone from his pocket. _The next Miraculous Moon isn't for a few weeks, what are you going to do until then?_

He paused, flipping open the cover for the cellular device, looking down at it. "We're going to stall." Pressing the top number in the quick dial list, he waited for the sound of dial tone to end, he cleared his throat as the call was received. "Nathalie."

* * *

 **[Campsite, 9:00AM]**

"Wake up, sleepyheads!" Alya shouted into Marinette and Adrien's tent, grinning when she found the two curled up in one sleeping bag. "You're going to miss most of the day, guys! It's not raining, so we should explore!"

"Five… more… minutes…" Marinette grumbled, rolling on her side, knocking into Adrien's back. Her eyes shot open as she lurched back, jumping upright. "A-a… What time is it Alya, why didn't you wake me up earlier?"

The sly grin across Alya's lips was enough for Marinette to die from embarrassment. "What happened to you two last night? Obviously, you found him, but what happened after—"

"I tripped and fell into the stream on the way back." Marinette looked at Alya, then to Nino "Wait, you two were sharing a tent, weren't we going to share, Alya?" Nino shook his head quickly, moving back to cooking breakfast. "What happened there?"

"You two were so late, no use both of you having to disturb Nino and I getting some shut-eye." her eyes moved to the tent as Adrien stirred. "What time did you guys get back, anyhow?"

"Probably around 2 am?" Adrien propped himself up, pulling over his backpack to rummage through it for a juice box. "It was pretty late, the moon was pretty anyhow." he popped the straw through the top of the box, looking up at Alya.

"Girl, did you get the pictures of the moon for me?" Alya redirected her attention to Marinette, who's face completely paled. Through all that had happened last night, she forgot the pictures for Alya? Marinette swallowed hard, handing the camera back to her friend. "Lucky for you, the next soltice moon is in two weeks, we can get the pictures together then!"

"Doesn't a solstice come once per season though, Alya?" Nino asked, stirring the cast iron pot before him, clearly absorbed more in making breakfast than on the conversation between his friends.

"If you remember, what makes Miraculous Island special is that there's two solstice moons in the summer. The first being the Sea Star Solstice, the second being the Miraculous Solstice — sailors would say the second moon would undo the magic cast upon them by the merfolk!" Alya smiled as Adrien spit out his juice. Alya laughed "Seriously, guys, you can't believe everything you read in books!"

Adrien nervously laughed, quickly shooting a look to Nino as the hot pot containing their breakfast began to boil over. Adrien leapt up to his friend's aid, fanning the flames of the campfire to no avail. "Careful, Nino!" he raised his hand, as if to grasp the handle, but instead curled his fingers back, the flames dying before he grabbed the pot, pulling it off of the fire and directly onto the stone next to it.

"Dude, you totally killed the fire!" Nino pulled his box of camping matches from his pocket, trying to get them to light again as Adrien moved over to Marinette and Alya. "Do you know how long it took me to light this?"

Alya smirked, "Actually, he didn't light it. I did." She walked over to the fire pit to help Nino re-light the fire, practically laughing as he swiped away the matchbox so she couldn't take all the glory. "Oh come on! Do you want to have a cold breakfast?"

"Did you freeze the fire to put it out?" Marinette whispered over to Adrien, seeing a slight entertained smile flashed across his face. "Did you think maybe you could've just froze the pot?" she raised her hand, violently curling her fingers inwards as the pot started to produce smoke. She retracted her hand almost instantly, looking Adrien as she moved her hand over a few feet, pointing at the fire.

 _You're going to get yourself caught!_ A voice danced through her mind, however she pressed forwards, the fire coming back to life, sparks flying in every direction as Marinette quickly lowered her hand. Adrien quickly pulled her back as Alya and Nino jumped, narrowly avoiding the sparks. _That was dangerous!_

Adrien checked Marinette's hand, then making the same motions with his own — nothing. "Looks like you're the only fire-starter here." hearing Marinette giggle shyly, he turned, looking at Alya and Nino, an entertained grin graced his face. "Seems you couldn't light it again, Nino! Really, how are you going to show the girls how it's done?"

"Must've been some embers left burning there for it to restart so quickly." Alya gave Nino a hard pat on the back, laughing as Marinette and Adrien sat to join them for a partially burnt, but mostly cold breakfast.


	7. Chapter 7

As the quad finished their breakfast, there was something amiss in the bay — however, this knowledge was unbeknownst to them as the filled up on their slightly burnt and mostly chilled food, then taking to the jungles to explore for a bit. Alya, naturally, decided to be amazing and pair Marinette with Adrien, much in Mari's favor but not for her shy behavior towards the boy.

Watching the other two wander towards the volcano, Alya looked at Nino. "They've been acting strange since this morning — also, all that muttering last night."

"Maybe they were talking fairytales or something?" Nino shrugged, lifting a palm branch as Alya ducked under. "Adrien, Dude, he was gone for about five hours."

"I have a feeling they're hiding something from us." Alya paused as Nino walked onto the white sands of the beach. "Where's the yacht?"

* * *

 **[Volcano, sometime before noon]**

"So, where was this cave the man with the butterflies attacked you in?"

Marinette put a foot upon the rock formation, observing the landscape around them. She shook her head. "I can't see it here, maybe it's somewhere on the other side of the volcano?" she kept walking, pressing her hand to the side of the basalt formation until she reached a flat 'wall' "I feel like it's here, but there's nothing here but solid rock."

Adrien thought of using cataclysm, but resisted, looking down at his ring. "Are you sure? Doesn't look like this is an opening." Adrien bent his fingers to his palm, then outstretching them, trying to freeze any moisture in the rock. "There's no way this thing's going to break. We're going to have to find another way in."

"The next Miraculous Moon, then." Marinette sighed "I felt that it was just open for the Solstice Moon, maybe it's connected to it?"

"Maybe, but we'll be waiting three weeks for that. We're supposed to head back tomorrow."Adrien scratched the back of his head. "What would we do, swim back?" Marinette felt jitters up her spine, watching him, then quickly turning away as the boy retracted his hand, noting the direction she had turned. He breathed, and under his breath, whispered as he pressed his hand against the rock. " _Cataclysm._ " A bright green flash pulsed out his ring, then across the stone wall — it appeared to be absorbed by the wall as the ground beneath their feet shook.

Marinette yelped as she jumped backwards, towards Adrien as the tremors gradually faded away. "What was that?" she watched as Adrien was continuing to push against the stone wall. "Its not going to open, don't hurt yourself!" She looked as a flash of green light emanated from around where the entrance should be, but then quickly vanished.

"Dudes? We've got a problem!" Nino's voice rang through the densely wooded jungle. Both Marinette and Adrien turned to see their friend out of breath, with Alya trailing behind him.

"What's going on?" Marinette went to meet with them as Adrien gradually admitted to himself that the door wouldn't open even if he tried. Looking back at his friends, he pushed himself off the stone wall to meet as well. "What's the problem, Nino?"

"Your dad's yacht is gone, dude!" Nino tried to explain what he and Alya were doing when the had came upon the beach to look out and see nothing but ocean. "We're not sure why, but it's gone!"

"The only reason Gorilla would move the ship would be because a fierce storm was about to move in. There's no other logical reason why he would leave us here." Adrien paused, looking at Marinette, whose face blanked immediately. "Let's look around the island, maybe they've anchored somewhere else?"

"If that's the case, we'll check the south side, you guys can stay here on the north side!" Alya ran off, dragging Nino behind her without any other questions. Marinette breathed a sigh of relief that Alya hadn't dragged her off, but looked questioningly at Adrien.

Adrien nodded in response to Alya before turning on his heel and heading towards the jetty. "What are you doing?" Marinette called after him, he looked over his shoulder briefly in response but turned quickly down the bank. Running after him, she looked at the boy as he stood barefoot on the rock formation, ocean waves splashing onto the smooth stone around him. "Adrien, come back, we should have a plan in mind before you get your feet wet!"

Adrien moved the water around him with a swift motion of his wrist, looking not at Marinette, but instead at the ocean. He paused for a second, noticing the girl had carefully walked onto the rock behind him, he turned. "A plan, right?" Marinette scooted closer to him as the water rushed around their feet, pushing her to share the only dry spot with him. "We check to see if the boat has left yet!"

"Nice plan, but Nino said that the yacht was already gone."

Adrien shook his head, looking at her. "They couldn't have gone far, we could catch up to them and jam the motor — then propel the boat back to the island using our powers!" He grinned as he loosened his wrist, the water surging over both their feet. Marinette raised her foot before crashing into him as she lost her legs.

"A-A-Adrien, your tail!" Marinette struggled under his weigh, seeing the compromising position that they had fallen into. She blushed, flustered, she pushed him aside as the water rushed around them. Trying not to give away that she had seen him like this before, she exhaled as he sat up on the rock, beside her. "You too? How?"

"You didn't figure it out until now?" Adrien grabbed her hand, pulling her towards the ocean. "We're wasting time, lets get to that boat!" waiting for another wave, he launched himself into the ocean, propelling with his tail, dragging Marinette in his wake.

"Adrien!" Marinette cringed as she was pulled under, breaking her hand from Adrien's as they both resurfaced. "I don't think our powers are strong enough to stop a yacht that big. We should call someone else, like…" she paused, not knowing if he'd key into there was another merman in the sea other than him. "… Chat Noir."

"Chat Noir?" he looked at her, puzzled. "Who's that? Like… Ladybug?"

"So you saw them too. Maybe they're hanging around the island — I'll look for them!" Marinette torpedoed away quicker than Adrien could catch her. Swinging around the reef, she felt for her earrings, spotting the bottom of the yacht in the distance she nodded. Placing her hand on her hip, she was about to transform when she brushed her hand past a rough patch. She looked down, a red sea star with five black spots had 'tattooed' itself to her hip. She swallowed, looking at it.

 _To stare is impolite, Marinette! You gotta catch up with that boat!_ the light voice danced around in her head, she narrowed her gaze at the sea star as it seemed to connect with her. _You gotta transform, Marinette!_

"Sea Star?" she raised her hand to her earrings, then looking around her to see if anyone was nearby. Marinette thought Adrien hadn't followed her, he couldn't swim as fast as her, right? She raised her head to the surface, catching a breath of air. "Transform me!" Watching as the sea star emitted a bright pink light that enveloped her, she torpedoed out of the glow and towards the boat.

* * *

Adrien watched Marinette swim off, much faster than he could catch up. He shook his head, pressing his hand to his throat, discovering something 'tattooed' on his chest. He looked down, seeing a black shell with a green edge attached to him "Ok, seriously? Now you show up?"

 _Why don't you wait a bit, Ladybug'll take care of it?_ a voice danced through his mind as Adrien scowled. ' _Fine, say the word_.'

"Shell… transform me!"

* * *

Ladybug had already pressed her body to the side of the ship, trying to scour the ocean for a sight of Chat Noir. Finally, she saw the merman flash out of reef below her. "About time! There's teens stranded on the island, and this boat is their only ticket home!" she pulled the hull of she ship, to no avail.

"Hey, you're going to pull the hull apart if you do that, how about we get a closer look?" Chat Noir grabbed around her waist, pulling her to the back of the ship, then up onto the deck. He breathed for a minute, pulling them a bit further than the water on the edge, he motioned for her hand. "We'll need to be quick, we can't spend a lot of time drying off." He pulled his own hand over his face, still with an arm around her, turning them both invisible. "You'll need to work quickly, m'lady."

Ladybug ignored the situation they were both in, bringing her hand over their tails and curling her fingers to her palm. "Why couldn't you do this?"

"It would be impawsible to sneak up on them with tails, don't you think?" he tightened his grip as his tail burned off, his claws painfully digging into her side. "Ah, that's hot…"

"There." Ladybug stood up, causing Chat Noir to loosen his grip, both of them becoming visible again. "Don't fall back in now, I'm not drying you off twice, Chaton." She pulled him up, then moving quickly and carefully up to the deck where the steering console was. She stopped briefly, looking around the door as Chat caught up with her, puling at her waist again as he pulled his hand across his face, invisibility cloaking them once again. "What—"

Chat quickly covered her mouth with his gloved hand, pulling her closer as he watched his own bodyguard walk by, surveying the deck before entering the captain's quarters. Chat hushed his voice to whisper in her ear. "I don't know about you, but I don't want to be caught by him."

Ladybug pushed his hand down, ducking around the corner of the captain's quarters with him, his other hand still raised to maintain their invisibility.

Gorilla hmphed as he looked at Nathalie, who was steering the ship. "If you understood Mr. Agreste's instructions, he said the kids would be safe on the island until we pick them up. We need to get the boat out of the way before that storm hits." she breathed, looking at the bodyguard. "It's an uninhabited island, with rich food resources. We were reassured they'll be fine until we get back."

Gorilla almost protested, placing a hand on the steering wheel, he huffed. Nathalie shook her head. "They'll be fine. Mr. Agreste insists that as soon as the storm has passed we can come back." she looked ahead as the mist thickened in front of the boat. "We're not going fast enough, we'll be lost to sea if we stay here any longer!" she sharply spun the wheel. Gorilla, Ladybug and Chat Noir were thrown to the side of the cabin, the latter's invisibility burning off of them as they were revealed to the secretary and bodyguard. "What, how'd you get in here?"

Ladybug sprinted to the wheel, pulling at it as Gorilla held down Chat Noir. "You have to turn around, rescue those kids from the island!" She tried to turn it, but Nathalie solidified her grip, looking down at the teen. "They can't survive weeks there on their own!" Nathalie threw her off the wheel, towards Gorilla, who caught her. Holding Chat under the other arm, he nodded to Nathalie. "They can't stay here, you're right."

Chat Noir struggled, reaching his hand for the wheel he whispered "Cataclysm!" pressing his hand against the wood, seeing it splinter as Nathalie released her grip. "Now we're all stuck here, what'd'ya say you explain why you won't go back for those kids?"

"We have a spare wheel in the brig." Nathalie seemed emotionless towards Chat's antics, motioning to Gorilla. "Throw them overboard, we don't need them to slow us down."

Gorilla nodded again, turning on his heel to head towards the deck, both teens struggling against his grip. He huffed again, swinging both his arms back, both Ladybug and Chat Noir struggling to hang on. Another 'hmph' as he swung both his arms forwards, launching the teens into the cold ocean depths.


	8. Chapter 8

Gorilla heavily tossed both of them out to sea - plunging the two of them into the roaring ocean below the boat. Chat Noir quickly grabbed onto Ladybug as his own transformation started to burn off. He pulled at her ankle, trying to keep a hold of her as they plunged into the salty waters below, then gripping her tail. Adrien tapped the shell on his chest as he struggled to remain above the waves, pulling Ladybug to the surface — her unconscious from the drop. He looked back up at the boat as the mist began to cloud the sea in front of them. "Darn it, but we have to get her back to shore, I'm not sure how long it'll be til she wakes up." He looked around, trying to get an eye on where he could possibly pull her ashore.

 _Why don't you take her back to the moon pool?_ he looked at the shell, narrowing his eyes at it. He shouldn't be hearing voices in his head, unless — _Yeah, its me speaking to you! Get back to that island!_ Adrien dove, pulling Ladybug along with him as he swam around the reef, and back towards the island. He came up for air again, looking around as the voice came through his mind again. _Why are you stalling? Get to shore!_

"Why? Who are you even?" Adrien shot back, holding the girl above the waves.

 _Plagg._

"And?"

 _I can't fill in much, just get to shore before this storm rolls in._ The voice echoed through his head, Adrien shook his head, swimming towards the entrance of the Moon Pool.

"I can't just leave her in there with no explanation, there's no other way out." Adrien pulled himself up on the rocks surrounding the tunnel, lifting Ladybug up beside him. "I shouldn't leave her unconscious either." He took a breath feeling for her pulse, then pressing an ear to her chest. "She's breathing, just not responsive, she must've hit the water head first." He sat up, rolling her onto her side he pressed a hand against her back, rubbing it as he tried to think what else to do to wake her up.

 _Why don't you give your purrincess a kiss?_ Plagg snickered as Adrien slowly raised his hand, raising a ball of water which separated from the ocean and floated over to them. _You're going to splash her, wow. Good job. A true romantic_. Plagg's voice was thick with sarcasm, Adrien contemplated if it was possible to remove a magic tattoo. Shaking his head, he dropped the cold water on Ladybug, who shot up almost instantly in response. Adrien launched himself back into the water, sweeping his tail under the reef and into the tunnel leading to the moon pool. _Wow, nervous, much?_

* * *

Ladybug shot up, looking straight ahead of her at… absolutely nothing. She looked around, the cold water running off her skin and down the rock shelf. What happened? She was just thrown off the boat… how'd she end up here? "De-transform me, please." Pink sparkles burned off of her as she looked down to the water, trying to figure out if she should wait until she dried off, or to swim around to the beach. She shook her head as the light voice echoed in her head again.

 _You should find Adrien! He might be worried about you!_

"Where should I look, though?" Marinette pushed off the rocky ledge, landing in the water, the current colder than before. "A storm is moving in, isn't it, where would Adrien go if there was a storm?" She ducked under the waves, opening her eyes to see the entrance to the moon pool. Not questioning why she was there, she pushed herself forwards, emerging on the other side. She grabbed at the side of the pool, hoisting herself up to one of the submerged shelves.

"About time you showed up, what happened out there?" She turned, seeing Adrien. He shook his head, pressing his palm to his forehead as he pulled himself up onto the ledge next to her, a bit too close for Marinette's comfort. He rested his chin on the edge of the pool, eyes moving from looking at her to the sea star next to him, placing his hand on it. "Is this a tattoo?"

Marinette nearly jumped out of her scales, pushing Adrien's hand back, she glanced back at him with wild eyes. He placed his hand back on the side of the Moon Pool, not breaking eye contact with her as she swallowed, hard. Her eyes traced from his to the shell mark on his chest. Almost launching forwards, she pressed a finger to it "IS THAT A TATTOO?"

"Of course not! My dad would kill me if I got one!" he looked up at her, finger pressed to her hip, a devilish(ly handsome) grin plastered on his face. "You didn't answer, is this a tattoo?"

Marinette launched herself onto the sand, instantly raising her hand over her tail to dry it, pink sparkles flying up around her, she turned to look at him. "See, it's gone if—" she noticed him staring at her wide eyed, she sat back down by the edge of the pool, peering down at him. "Yes, I just dried myself off using that same power I used to relight the campfire, what's wrong?"

He shook his head, distinctly remembering Ladybug drying Chat off in the same manner. "You probably still have the tattoo." he reached up for her waist, Marinette violently lurched backwards as his hand brushed the top of her jeans.

"IF I DIDN'T LIKE YOU SO MUCH, I'D SLAP YOU!" Marinette clasped her hands over her mouth, her cheeks quickly flushing a shade of hot pink. She slid her palms over her face, not looking at him. No, no. Now was not the time to confess your crush to him, Mari! She didn't dare look up as Adrien hauled himself out of the Moon Pool, his tail curling around, tapping her on the knees.

"So, you like me? Not just because of this fishy situation we're in?" Adrien laid back on the sand, looking up through the top of the volcano, towards the sky. "I'm sorry, I wanted to see if the tattoo goes away if we change back, I should've asked first."

 _Curiosity kills the cat, don't you know that?_ Plagg droned, annoying Adrien.

Marinette peeked at his tail, lifting a hand off her cheek she raised her hand over his scales, drying them as she brushed the hair out of her face. She looked back at him, an apologetic smile displayed for her. She watched as Adrien's tail turned into a frenzy of green sparkles, flying up towards the sky above them. Quickly she turned, pulling up his shirt without hesitation "This is revenge!" she held his shirt up for a minute, the hot pink flush returning to her cheeks when she had realized what she had done.

"Is it still there?" Adrien snapped her attention back to the matter at hand. Dropping the edge of the fabric, she shook her head. He breathed a sigh of relief, awkwardly sitting up — Marinette in the way of him propping himself up completely. "So, we don't have the tattoo when we're human. Well, I know I don't, at least." Mari shot him an unamused glance, turning her back to him as she stood up and walked back to the pool.

"So what are we going to tell Alya and Nino?" Marinette sat on the edge, legs dangling into the blue water as she counted down from 30, then resting her pink tail on the side of the pool. "Did we find out anything from Ladybug or Chat Noir about the yacht?"

"Chat said he and Ladybug had boarded the yacht, but were thrown off by Gorilla. Apparently my dad gave the order to get away from the island because of a storm coming?" Adrien tried to think back to what happened on the boat, looking at Marinette. "When Ladybug was thrown off the boat, she was knocked unconcious. When I met up with Chat, he was just pulling her ashore. He told me to wait at the Moon Pool to be safe."

"Ladybug swam past me on the way in." Marinette was just putting the pieces together, she looked back towards Adrien, who had stood up to come sit beside her, not touching the water yet. "She also told me to head to the Moon Pool."

"I'm not sure how we're going to tell Alya and Nino the boat isn't coming back." he put his hand on her knee — er — tail, getting ready to jump into the Moon Pool when he saw something in the water. "Marinette, dry off, quick!" Pulling the girl back, he looked down through the water as through the tunnel emerged their friends. He checked Marinette, watching her try to dry her scales, he dove in front of her, grabbing her other hand. "How long do you think you'll be?"

"They're not drying as fast as last time, maybe a minute?"

Adrien figured they didn't have that long. He brought his hand across his face, turning them both invisible, just as the surface of the moon pool broke, two free divers emerging — not just any free-divers though, no! They were Alya and Nino. Marinette almost gasped, but Adrien pulled her closer to him before she could get the sound out.

"I don't know where they could be." Alya removed her diving mask, pulling herself out of the pool, Nino in tow. "There's no other entrance to this cave, but we've searched the entire island. There aren't any other hidden caves on this island, are there?"

"I don't know, ladybro, but there's footprints in the sand here. If this place is so isolated, it should've been undisturbed." Nino stood close to where Adrien held Marinette, then looking at the cave wall. "It's almost homey in here."

Marinette tugged Adrien's shirt, trying to signal to him she had regained her legs, he still held her tightly, making sure not to blow their cover. She looked over Adrien's shoulder, one word uttered from her lips. "Octopus."

Adrien looked back, a gigantic black and purple octopus had crawled over the rim of the Moon Pool, Alya and Nino totally unsuspecting as they were still looking for a land entrance to the cave. He stood up, shakily holding the invisibility over them, Marinette still hanging on to him, he whispered "I think we can both use our powers to push it back into the pool, after that we go towards Nino, he seems to of found a land exit."

Marinette nodded, reaching out her other hand, the octopus was slightly pushed back. Adrien raised his own hand, pushing it further into the pool. With a splash, the gigantic creature was pushed back into the pool. Adrien turned to run, hand over his face, other hand locked in Marinette's. Both of them sprinted around Nino, becoming visible while the boy wasn't looking "Nino!" Marinette waved, briefly… then it hit her.

A scream from the inside of the cave, Nino looked from Mari to Adrien, then turning on his heel to head back into the cave.

"We left Alya in the cave with the giant Octopus." Adrien looked at Marinette, her already making a mad dash back to the cave. He looked aside, making sure she didn't glance back. "Plagg, transform me."

 **A/N:** Someone asked for fluff, this is as fluffy as it's going to get (for now, it is rated T for a reason). Anyhow, I'm sleep deprived from the last few weeks, is it showing in my writing? I hope not, I really want to continue this story. Not trying to make it confusing either, instead of Kwamis, they get tattoos - sweet deal, right? _It totally gives aaway their identities but Mari and Adrien... don't see that. Its great_. Anyhow, onwards! 


	9. Chapter 9

High above their heads, in the rocky chamber above them, the man stood — his hand pressed to a pedestal containing the island's map, fingers just hovering over the engraving for the Moon Pool. He chuckled to himself as a black and purple butterfly landed upon the stone, tapping the symbol to tell it where to go.

"Seems like my plan is going perfectly." he straightened his back, watching the butterfly meld into the map. "First, I'll activate the Moon Pool — they'll lose their powers — I'll take their Miraculouses!" he stopped himself from cackling "There was no reason for them to steal them from the pool in the first place, teenagers have no respect these days."

He tapped the map again, watching the Moon Pool light up in bright blue. "Swim away, my little Akuma. Defeat those who steal from Hawkmoth!"

* * *

 **[Moon Pool Grotto, with an octopus]**

Marinette bolted into the cave, past Nino, straight to Alya. "What's going on, I heard—" she turned, seeing she was face-to-face with the octopus from before. The shell's voice rang through _You have to transform! You can't take it on alone!_ Marinette put her hand up, knocking the creature back slightly as she helped up her friend.

"Alya we have to get you out of here—"

"— the entrance just closed!" Nino rushed in, looking at the octopus, hands raised. "Pick on someone your own size!"

Marinette raised her hand, the creature shuffling away from her as she tried to use her powers without being noticed. She looked up, a sucker-filled tentacle almost crushing her as she was pushed out of the way. "Chat Noir!" the teen, clad in black leather, sliding, pulling both her and Alya to the side of the grotto.

The octopus lashed against his back, his spine sharply straightening in pain. "A-aaah." Hesitantly, he stood, narrowing his eyes at the sea creature, turning. Marinette could see water droplets on his back, rolling off the leather. "Stay here, I have a fish to fry!" he dug his toes into the sand, bolting forwards as Marinette watched the octopus raise it's arms again. "CATACLYSM!" Chat's ring flashed, his hand filled with pulsating dark energy as he pressed his hand to the octopus' head, but was blocked by another tentacle. He was whipped backward, flipping to land on his feet as Nino stopped him from sliding into the wall. "Darn…"

"He's hurt!" Alya bolted from the hiding spot, her friend trying to catch her hand before she bolted out — a tentacle wrapping around her as the octopus lifted her into the air.

* * *

 **[The Cave Lair, above]**

"They'll have no choice but to dive in and save their friend! I'll take away their powers! I'll be victorious!" the man pressed his hand into the map, the Moon Pool's symbol flashing a deep blue. "I have saved enough of the moon's power, just for this moment!"

* * *

 **[Moon Pool Grotto, still with an octopus]**

Chat's back arched in pain, fighting against the sting where the octopus had lashed him, he struggled to look up. All he knew was Alya was being lifted into the air, and he only had five minutes until he transformed back into Adrien. He looked aside, Marinette still hidden, he tried to signal to her, a failed attempt as the girl tried to make herself invisible, failing.

"Dude, look at the water!" Nino pointed at the pool, which had begun to bubble. He pressed a hand to Chat, helping him straighten his back. "Alya, don't panic! We'll get you down from there!" he looked at Chat "How are we going to get her down from there?"

Marinette continued to pull her hand across her face, trying to become invisible. She couldn't transform, they'd see. But she needed to help Alya — Chat caught her eye, signaling her. She looked over at him, he put his hand out, fingers curling into his palm. He wanted her to make the water boil? She nodded, her hand curling like he had done, the water surging around the octopus — the cephalopod panicking as it's arms lashed out at them. She launched herself from her hiding place, diving under one of the arms, sliding into Chat Noir's chest. "Do you have a plan, kitty?"

"Don't… touch… the water." almost growling, her looked at Nino, then to her. Chat stood taller, still wincing against the pain writhing up his back. He looked down at Marinette, smirking slightly. "I have the purr-fect plan." he quickly grabbed her, pulling a hand over his face. There were only minutes left in his transformation, he rested his chin on her head, speaking softly so the others wouldn't hear. "I need you to use your powers to lower the water in the pool. I'll help. We need to get it low enough that one of us can grab Alya, okay?"

"I have a better plan." Marinette turned, passing around Chat Noir, pressing her back against his. "Keep that invisibility up, I need it." Lowering her voice, she held onto his hand, the shared invisibility cloaking them from view. "Sea Star… transform me." a flurry of pink sparkles rose from where her feet would be, flipping above Chat Noir, Ladybug released her grip on his hand, the invisibility wearing off as she held onto the wall.

"Marinette?" Chat looked around him, worriedly. Luckily she had been stealthy to flip above him, both him and Nino unaware to her transformation — seriously, guys? Did you miss the sparkles? — he turned, looking at Nino "So, do you have a plan?"

Ladybug jumped down from the wall, looking up at the octopus. "You're going to put her down." she walked to the side of the suddenly (seemingly) calm creature. "Lucky. Charm." materializing out of a pink light, a large fish hook landed in her hands. She glanced around the room — chat's tail, a branch overhanging the crater, an air tank — Nino probably brought that in case him and Alya were to dive further. She nodded, solidifying her plan in her head as she turned. "Chat, your belt; Nino, the air tank."

Nino nodded, quickly walking in front of the octopus, watching it's movements — or it's stillness? — carefully as he picked up the air tank, walking over to Ladybug. A belt placed in her other hand, she got to work, tying the fish hook to one end and the air tank to the other. She tossed the hooked end over the branch, holding onto the air tank as she watched the hook swing around the tentacle holding Alya. A gloved hand pulled the lid off the air tank, the container sizzling, then shooting out of Ladybug's hand and into the rock wall behind her — the tentacle was hoisted into the air as Chat Noir jumped to save the girl from it's suckered grip, pulling off a blackened sea star from the slimy skin of the octopus.

Tossing the sea star to Ladybug, he landed on the edge of the moon pool, hearing the roaring water behind him, he turned, looking from the shrinking octopus to the blue waters — resembling the water the night he had transformed. Letting Alya out of his own grip, he jumped back as a tentacle swung out at him… directly hitting Alya in the stomach, knocking her into the pool as the sea creature shrank and swam off.

"ALYA!" Nino and Ladybug ran over, looking at the girl in the pool as the bubbles continued to roar around her, a panicked look behind her glasses as Ladybug placed her hands in front of herself, trying to lift the water to get her back.

* * *

 **[Cave Lair, Above]**

"You have defeated my Octopus, Ladybug, but next time, you won't be so lucky!" the man lifted his hand off the moon pool engraving, the flashing blue light fading away into the cold stone.

* * *

 **[Moon Pool Grotto]**

The bubbles ceased, the blue glow of the pool fading to a turquoise as Chat ran forwards to pull Alya out of the water, trading positions with her and diving into the pool, under the tunnel and out to the ocean. Ladybug looked at her friend as she stood, still stunned by her experience. Alya shakily inhaled, then spoke, looking at the water for Chat. "At least I'm not a fish."

 **A/N:** omg I suck at writing action scenes, but I wanted to include a battle in this. After this, it'll follow some good H2O-ness... mmm, wholesome XD ... well, anyhow, til the next chapter, guys! 


	10. Chapter 10

**[Back at the Campsite]**

Alya pulled Adrien's towel from his backpack, slinging the cloth over her head as Nino followed her. She pulled her phone from her pocket, placing by the fire, in the sunlight as she dried her hair. Looking around, she saw neither Adrien or Marinette at the campsite, and instead looked at Nino as he sat back beside the fire — obviously trying to light it again.

"Thank goodness for those dudes earlier, or we would've been fish bait!" he smiled, watching his friend take a seat on the log next to him. "Too bad both of them disappeared so quickly though, I would've liked to ask for their names."

"Adrien and Marinette also ran out so quickly, where could they—" she stopped, looking up as the two moved their way through the undergrowth, towards the campsite. Springing upwards, Alya ran to the edge of the clearing "Marinette! Adrien! Where have you guys been?"

"Still trying to see where the yacht went." Marinette raised her hands, showing she had no clue with a empty wave.

"You guys didn't run out after us, what went down with the octopus?" Adrien ducked under a branch, pressing his hand past a bush as they wandered into the campsite.

"You wouldn't believe it, but two superhero dudes came in and saved us from it. You totally missed it!" Nino motioned them to come over and sit next to the campfire.

"Saved?" Adrien looked from Nino to Alya as she sat down. "Who were they?"

"No clue, they didn't even say their names." Alya reached her hand towards Nino and the box of matches as he still struggled to get the fire lit. He quickly swiped them away as she retracted her hand in surprise. The campfire combusted. Everyone looked at the fire in surprise as Alya jumped back. "Wait, did this fire just light on it's own?"

Adrien looked at Marinette, who shook her head quickly in response. Marinette didn't light the fire, Nino didn't light the fire, he couldn't light the fire with his powers, it had to be… "Alya, can you do that again?" he quickly motioned his hand behind his back, extinguishing the flames. Marinette shot him a look, but looked again at her friend.

"Sure, but I'm not sure what I did." Alya raised her hand towards the fire, curling her fingers back again in the same surprised fashion she had done before. Spontaneous combustion. A grin danced across her face. "Did you guys see that?"

 _She's got powers!_ Marinette nodded at the voice in her head, watching Alya try to light every dry piece of scrap she saw. _We should stop her before she sets the whole island on fire_. Marinette grabbed her arm, leading her back to the fire. "Breakfast first, then we'll decide what to do for the day."

Alya nodded, beaming at Nino. "I lit the fire and you didn't!"

* * *

 **[Beach, after breakfast**

Alya shuffled her toes in the sand, had having changed into an orange and magenta bikini, she pulled Marinette behind her towards the lifeboat. "Even if we're stuck here, we should at least have fun while it lasts!"

Marinette, wearing Adrien's t-shirt tied tighter around her midriff and a really short pair of shorts Alya had brought, dug her heels into the sand as the boys followed them onto the beach. "There's a storm coming, we shouldn't swim right now!" Marinette tried to brake further, instead falling face-first into the white sand. She let Alya help her up as Nino and Adrien caught up with them, Nino stopping to dump his free-diving gear into the lifeboat.

"I'll wait with Mari on the beach, you two go enjoy yourselves." Adrien grabbed her shoulder, motioning to Alya and Nino to go on ahead without them, taking the hint, they both waded into the waves. "Now we can talk—"

"We still have to figure out how to turn back, and we need to figure out how Alya's one drop into the Moon Pool gave her fire powers." Marinette quickly quipped, looking at Adrien, who pressed his hand to his chin, in thought.

"Guys?" Nino yelled from the shallows, not grabbing their attention completely, so he tried again. "GUYS?!"

"What was that Nino?" Marinette yelled back, looking over the boat, her eyes quickly snapped from Nino, to Alya, and back to Adrien. She shook her head, finding the boy in just as much shock as she was "Are you going to get her, or am I going to get her?" She watched as Nino lifted Alya up, an orange tail descending from her waist and falling over his arm as he carried her, bridal-style, over to them.

"Guys! I'm a fish! A freakin' fish!" Alya was freaking out, squirming in Nino's grip as he struggled not to drop her onto the sand. "What are we going to do?" her tail whacked Nino's thigh, the boy squeaking slightly from the impact.

"M-maybe if you dry off, you'll turn back?" Marinette shrugged, looking at her friend as Alya raised a hand, about to say more about her predicament. Water droplets flew off Alya's hand, spraying Marinette in the face, she jumped from shock. Looking around, she ran towards the ocean and dove into the crashing waves.

"MARI!" Alya looked over Nino's shoulder as her friend disappeared beneath the surf. "Nino put me down, please. I'm going after her—"

"—I'll get her—" Adrien started to take his shirt off, but Nino had already set Alya back into the water, setting her into the ocean. "NINO!"

Nino turned around, shrugging. "She said please, bro."

Adrien moved quickly, pushing the bow of the lifeboat off the sand and jumping into the vessel. "Start the motor, Nino! We have a mermaid to catch!"

* * *

 **[Out on the Reef]**

Marinette dove past a coral formation, looking around as she noticed no one had followed her into the water, she swam towards the surface, taking a mouthful of air before diving again. She had to swim around the reef to get to the rock shoals, then she could emerge dry without revealing her tail to them. She turned, looking up at the bottom of the lifeboat, which skimmed past her — she swam back towards the surface.

She watched Nino quickly turned the craft, Adrien then leaning out to grab her hand without a fear of getting soaked. Slowing down, Nino idled the motor as Marinette was pulled into the boat. "Dude, she's—"

"Nino, stay focused, Alya?" Adrien put a towel around Marinette as he dried his own hand. "Are you alright?"

"Where's Alya?" she curled her fingers, using her powers to dry her own tail.

"She went swimming to find you, I tried to stop her but—" Adrien shook his head as pink glitter rose from Marinette's tail, turning her back to her human form. "—Nino, do you have the fish finder on?"

"Yeah, but I don't see her, at all." Nino sat back, looking at Marinette. "So, how did you get the tail?"

Marinette looked at Adrien, wondering how he couldn't of filled Nino in prior to picking her up. Unless… did Adrien tell his friend the same happened to him? She shook herself out of her daze, hearing the engine cut. "Wait, why are you stopping here?"

"I'm not, the engine cut out on it's own!" Nino pulled the cord a few times, trying to get the motor to start again — the fish finder rapidly beeping out of control before powering off. Nino turned, pressing the reset button a few times, before giving a nervous glance to Marinette. "Can you check if there's seaweed in the rotor?"

Marinette was about to complain, when a splash was heard from overboard the vessel. Turning, she watched as the boat rocked dangerously from side to side. Another splash. Adrien raised his hand, pushing Nino out of the way as he extended his arm from the back of the boat. Marinette watched him as the boat shook again.

"Dude, you're going to fall in." Nino went over to his friend as Adrien twisted his hand around, the sudden motion of the boat knocking both Marinette and Nino back as Adrien used his powers to propel the boat onwards. "Dude—"

"I'll explain later, we need to find Alya." Adrien looked back at them, Marinette nodding as she came over, outstretching her own arm to help propel the boat. "Mari, maybe you should check the reef, I'll keep the boat nearby."

Another splash, the boat lurched, almost flipping over completely. Nino ran over to the side, hoping to keep them above water "There's something trying to sink us!" He peered over the edge, squinting his eyes at the clear water, seeing nothing below them but reef. An invisible hand grabbed his jacket, pulling him down to the water. He jumped backwards "GUYS, THERE'S—" the boat rocked violently, Nino grabbed his extra air tank, strapping it onto his back as he reached for the blue flippers on the bottom of the boat. Suddenly, the boat capsized, dumping the three of them into the ocean.

Adrien plunged into the ocean, releasing his powers from the stern of the lifeboat, he gazed up towards the surface. He saw Marinette's tail reappear as Nino's flippers floated past him, he looked around, snapping out of his shock-induced trance, snatching the flippers as his own tail appeared. A quick bolt back to his friends, resurfacing, he put his hand on the side of the lifeboat. "Are you guys okay?"

"Dude! You have a—"

"We'll explain later!" Marinette and Adrien both quipped in unison, glancing at each other, right as the motor for the lifeboat magically powered to life — the rotor slicing against air as the boat still remained capsized.

"It seems you're in a bit of a pinch!" a mermaid surfaced before them, Adrien swallowed hard, looking at her features, a black tail with magenta markings — almost glowing in a sequence from the smallest dot out the the largest line. Like a wifi signal? "I am Lady Wifi, and I'm here to collect Ladybug and Chat Noir's miraculouses — you haven't seen them, have you?"

"Who?" Nino asked, looking from her to his friends. "Wait, are those the people who saved Alya and I earlier? Because they were awesome!"

Adrien passed Nino's flippers to him, then diving under the capsized boat, into the air pocket maintained by the overturned hull. He inhaled sharply, preparing himself "Plagg, transform me." Watching the green light burn over his tail, up to his neck, he closed his eyes as he swam back out to Marinette and Nino, brushing his own black tail around Nino and Marinette as he resurfaced. "Sorry, Lady Wifi, but your signal is about to be cut!"

* * *

 **A/N: Hi all, long time no story! Sorry for the break there, I was driving home from college and then Christmas happened - basically my life turned upside-down! If my writing seems a bit topsy-turvy, I'm getting back into the swing of things right now. Hopefully the updates for H2N will be a bit more regular from now on. Thanks for reading! - RicePoison**


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